<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        ul{
            background-color: pink;
        }
        li{
            background-color: red;
        }
    </style>
</head>
<body>
    <ul>
        <li>11</li>
        <li>22</li>
        <li>33</li>
    </ul>
    <script>
        var ul = document.querySelector('ul');
        ul.addEventListener('click',function(e){
            console.log(e.target);//点哪里是哪里，步步高点读机
            console.log(this);//监听的是ul就是ul

        })
    </script>
</body>
</html>